Process for preparing printing-plates in a grained manner.



UNITED STATES PATENT, OFFICE.

HANS smEcKER-AUFERMANN, or MUNICH, GERMANY.

PROCESS FOR PREPARING- PRINTING-PLATES IN A GRAINED MANNER.

1,014,740. No Drawing.

Specification of Letters Patent. Application filed January 11, 1910. Serial No. 537,523;

Patented Jan. 16, 1912.

To all whom it may-concern:

' Be it known that I, HANs S'rnnoKnR-Am FERMANN, a subject of the German Emperor,

the subject matter of my previous Patent Number 954,412 issued April 2, 1910, and relating to the preparation of a layer which is sensitive to the li htand decomposed into grains, onemay sti l em loy other glues in which under certain con itions also no mixing takes place between the Arabic gum and the various kinds of glue, but a separation in the form of small drops of the Arabic gum in themiddle of the glue. One may then by means of suitable conditions cause the various se arate small drops to unite themselves to orm larger and larger drops. These glues are besides all the so called fish glues which have the characters of the Le Page glue and of the photoengraving glue, the true fish glues andother kinds of lue containing chondrin and glutin and which may also be called chon-- drogens and collagens. These are the cartilage glues and the bone-glues (harts horn, tendons, connective tissues, fish scales, whale bone, fish bladder whale larder) as well as the skin glues which have been disintegrated by bacteria or ferments, by long boiling, or by means of sucrate of lime, acetic acid, ammonia, hydrate of chloral or in any other manner. One may still employ in the place of the fishglue the glues called cold glues which are to. be found in the trade. Mixtures of severalkinds of the glues cited above are also suitable for replacing the fish glue. All these glues have the property of being dissolved 1n water easier than the Arabic gum or to absorb the water more rapidly than the latter. Now when these glues having a concentration varying between 1.1 and 1.6 and Arabic gum having a concentration varying from 1.1 and 1.6 are mixed, the proportions of themixture of both varies between 1.1 and 1.8 and said ,more rapidly than the Arabic gum so that a long time before the Arabic gum is swolleno and has allowed the etching liquid to pass, the glues will have been passed through by the etching liquid even in those parts of the layer, which have been most exposed to the action of the light. It is readily understood that in this case too, the Arabic gum which I is embedded in the shape of a grain or vein in the layer of glue applied. to the metal plate, opposes a relative resistance to the action of the etching liquid. When using such glues, one may follow in general the lndications and recipes given in my previous Patent No. 954,412, April 2, 1910, for the composition of the layer; however it is necessary in each peculiar case to take into account the slightly different character of the glue from the point of view of its viscoslty.

If desired, there can be substituted for a portion of the amount of Arabic gum required cheaper kinds of gum .and mucilage as well as rosins, paraflin, wax, solid or soft liquid fat -(oil) et cetera, which substances like Arabic gum are adaptedto resist the action of etching. Or theArabic gum can beta-lined in any well known manner, as for instance by mixing a solution of Arabic gum with -a solution 0 chrome alum, before it'is mixed with the glue.

Having now fully described my said in- I spreading the mixture as a coating over a metal plate, leaving the late at rest so as to cause small drops 0 the Arabic gum solution to settle -=in the said mixture of solutions of Arabic gum and'of. glue containing chondrin and glutin, causing the said coating todry so as to render the'said drops of Arabic gum resisting tothe action of the etching, exposing the plate under a suitable image and directly etching the plate thereafter with solutions offerrlc chlorid, 110

substantially as and for the purpose set forth.

between 1.1 and 2. A process for preparing printing plates in a grained manner for monochrome and polyc rome printing, consisting in preparlng a chromated mixture of a solution of glue containing chondrin and glutin, the

concentration of which solution varies between 1.1and 1.6 and an aqueous solution of Arabic gum the concentration of which varies between 1.1 and 1.6 and another substance adapted to resist the action of the etching the proportion of said solutions in the mixture varying between 1.1 and 1.8,

. glue containing chondrin and glutin, the

concentration of which solution varies between 1:1 and 1:6 and an aqueous solution of Arabic gum the c ncentration of which varies between 1 :1 and 1:6 anda suitable tanning agent, the proportion of said solutions in said mixture varying between 1:1 and 1:8, coating a metal plate with this mixture, leaving the metal plate thus coated at rest, drying the coating of the metal plate, exposing the coated plate under a suitable image and etching it directly after the exposition by means of solutions of ferric chlorid, substantially as and for the purpose set forth.

4. A process for preparing printing plates in a grained manner for monochrome and polychrome printing, "consisting in preparing a chromated mixture of a solution of' pure glutin, having a concentration varying between 1 :1 and 1 :6 and-an aqueous solution of Arabic gum having. a concentration varyingfromdgi and 1:6 the proportions of both solutioii's varying'between 1 :1 and 1 :8, spreading the mixture as a coating over a metal plate, leaving the plate at restso as to cause small drops of the Arabic gum solution to settle in the said mixture of solutions, causing the said coating to dry so as to render the said drops of Arabic gum' resisting to the action of the etching, exposing the plate under a suitable image and directly etchingthe plate thereafter with solutions of ferric chlorid, substantially as and for the purpose set forth.

5. A process for preparmg printing plates in a grained manner for monochrome and polychrome printing, consisting in preparmg a chromated mixture of a solution of pure glutin, the concentration of which solution varies between 1 :1 and 1 :6 and an aqueous solution of Arabic gum the concentratially as and for the purpose set forth.

tion of which varies between 1:1 and 1:6 I

and another substance adapted to resist the action of the etching, the proportion of said solutions in the mixture varying between 1 :1

and 1 :8, coating with this mixture a metal plate, leaving the metal plate thus coated at rest, drying the said coating, exposing the said coated plate under a suitable image and etching it directly after the exposition,

with solutions of ferric chlorid, substantially as and for the purpose set forth.

6. A process for preparing printing plates in a grained manner for monochrome and polychrome printing, consisting in prepar- 1ng a chromated mixture of a solution of pure glutin, the concentration of which solution varies between .1 :1 and 1:6 and an aqueous solution of Arabic gum, the concentration of which varies between 1 :1 and 1:6 and a suitable tanning agent, the proportion of said solutions in said mixture varying between 1:1 and 1:8, coating a metal plate with this mixture, leaving the metal plate thus coated at rest, drying the coating of the metal plate, exposing the coated plate under a suitable image and etching it directly after the exposition by means of solutions of ferric chlorid, substantially as and for the purpose set forth.

7. A process for preparing printing plates in a grained manner for monochrome and polychrome printing, consisting in preparing a chromated mixture. of a solution of a mixture of ure glutin with a glue containing glutin, aving a concentration varying between 1 :1 and 1 :6- and an aqueous solution of Arabic gum .having a concentration vary- -in from 1:1 and 1:8, the proportions of mixing both solutions vary ng between 1 :1 and 1 :8, spreading the mixture as a coating over a metal plate, leaving the plate at rest so as to cause, small drops of the Arabic gum solution to settle in the said mixture of solutions, causing the said coating to dry so as to render the said drops of Arabic gum resisting to the action of the etching, exposing the plate under a suitable image and 'directly etching the plate thereafter.

withsolutions of ferric chlorid, substanaqueous solution of Arabic .gum, the concentration of which carries between 1 :1 and 1 :6, and another substance adapted to resist the action of the etching, the proportion of said solutions in the mixture varying between 1:1 and 1:8, coating with this mixture a metal plate, leaving themetal plate thus coated at rest, drying the said coating,

exposing the said coated plate under a suitable image and etching it directly after the exposition, with solutions of ferric chlorid, substantially as and for the purpose' set' forth.

9. A process for preparing printing plates in a grained manner for monochrome and polychrome printing, consisting in prepar mg a chromated mixture of a solution of a mixture of pure glutin with a lue containing glutin, the concentration 0 which solu tion varies between 1 :1 and 1 :6 and an aqueous solution of Arabic gum, the concentration of which varies between, 1 :1 and 1 :6- and a suitable tanning agent, the proportion of said solutions in said mixture-varying between 1:1 and 1:8, coating a metal plate with this mixture, leaving the metal plate thus coated at rest, drying the coating of' the metal plate, exposing the coated plate 20 7 under a suitable image and etching it direotly after the exposition by means of solutions of ferric chlorid, substantially as and for the purpose set forth.

In testimony whereof I have hereunto set 25 my hand in presence of two witnesses.

HANS STREGKER-AUFERMANN. Witnesses: LOUIS MUELLER,

MATHILDE K. HELD. 

